Printer Mark Detection Using Integrated Signal Change
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Solution Overview
Problem
Existing printer technologies face challenges in detecting a detection area on a sheet surface, particularly when the reflectance of the blank sheet portion changes, leading to incorrect mark detection due to the need for frequent threshold adjustments.
Innovation Solution
The implementation of a printer with a conveying unit, sensor, acquisition unit, detection unit, and printing control unit that calculates and uses an integrated value of the detection signal's change amount to detect the detection area, allowing for continuous detection without requiring threshold resets, even when the blank sheet level changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If threshold judgment is performed on AD values from a reflective sensor to detect marks or gap portions, then mark detection can be achieved, but frequent threshold adjustments are required when blank sheet reflectance changes, leading to detection errors
Solution Approach 1:
The patent creates a reference signal by copying the detection signal waveform and using its leading edge as a stable reference point for mark detection, eliminating the need for frequent threshold adjustments when blank sheet reflectance changes
Solution Approach 2:
The patent changes the detection parameter from absolute AD value threshold judgment to relative timing-based detection by comparing the detection signal waveform against a reference signal, making the detection immune to reflectance variations
2Reliability
If a reflective sensor and threshold judgment method are used for detection, then mark detection functionality is achieved, but detection reliability deteriorates when blank sheet level changes
Solution Approach 1:
The patent uses the detection signal waveform itself as feedback to generate a reference signal, creating a self-adapting system that automatically compensates for blank sheet reflectance changes without external intervention
Solution Approach 2:
The patent performs preliminary waveform copying and reference signal generation before actual mark detection, establishing a stable reference framework that adapts to current blank sheet conditions and enables reliable detection
3Productivity
If traditional mark detection methods are used, then printing position control can be achieved, but production costs increase due to frequent threshold adjustments and detection errors
Solution Approach 1:
The patent enables the detection system to automatically adapt to blank sheet variations through self-generated reference signals, eliminating the need for operator intervention and threshold adjustments, thereby reducing downtime and increasing productivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables reliable and efficient detection of the detection area, reducing the need for frequent threshold adjustments and allowing for the detection of marks with varying reflectance levels, thereby improving printing accuracy and reducing production costs.
Implementation Method 1
a sensor configured to output a detection signal in accordance with a surface of the sheet conveyed by the conveying unit
Data Source
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AI summary
A detection device (50) includes a conveying unit configured to convey a sheet (P) having a detection area (M) on at least a portion of a sheet (P) surface; a sensor configured to output a detection signal in accordance with a surface of the sheet (P) conveyed by the conveying unit; an acquisition unit configured to acquire, at a predetermined interval in accordance with conveyance of the sheet (P), the detection signal output from the sensor; a detection unit configured to detect the detection area (M) based on an integrated value of a change amount of the detection signal acquired at the predetermined interval by the acquisition unit; and a printing control unit configured to control a printing position for printing on the sheet (P) based on the detection area (M) detected by the detection unit.